1. Field
Example embodiments relate to methods and apparatuses for performing pattern alignment to die, and methods and apparatuses for generating patterns on workpieces.
2. Description of Conventional Art
In the packaging and assembly industry, stacked structures are becoming more common. Often, however, it is relatively difficult to accurately match a structure on a subsequent layer with a structure on a previous layer.
One example of a process requiring relatively accurate matching of structures is the stacking of dies on top of each other where the second die must be aligned relatively accurately with the first die to create sufficient contact between the two dies.
Another example is a fan-out or embedded die process in which a first structure is composed of mounted dies, and a second structure is a conductor pattern or via hole pattern (e.g., a build up metal patterned with lithography or laser drilled via holes), which must be aligned accurately with the first structure (e.g., the pads on the dies).
Conventional pick-and-place machines are capable of determining the local alignment of dies on a workpiece, and then using the local alignment together with alignment fiducial(s) or other measurable features on the die to align the die in the correct position on the workpiece.
In a conventional process in which two or more dies are stacked on top of each other, a first layer of one or more dies is accurately placed with a relatively slow pick-and-place machine and the second layer of one or more dies is also placed with a relatively slow pick-and-place machine.
Conventionally, each die must be placed relatively accurately on a workpiece because conventional patterning equipment (e.g., aligners, steppers, etc.) have somewhat limited capabilities to individually align to each die without sacrificing (e.g., significantly sacrificing) throughput (e.g., TAKT). Thus, conventionally, patterning equipment sacrifices speed to achieve the necessary accuracy of the pick-and-place machine.